What a Limited-Slip Differential Does, and When You Need One

An open differential lets your driven wheels turn at different speeds, which is essential for cornering. Its weakness is that it always follows the path of least resistance, and that is where an LSD earns its place.

What an open diff gets wrong

A standard open differential sends equal torque to both driven wheels, but torque follows the wheel with the least grip. Lift a wheel over a bump, or unload the inside tyre mid-corner, and that wheel spins uselessly while the one with grip gets nothing. On a hard launch or a wet exit, this shows up as one spinning tyre and no drive.

How a limited-slip diff helps

An LSD caps the speed difference between the two wheels, so when one starts to slip the diff transfers more torque to the other. A clutch-type or geared (Torsen-style) LSD does this mechanically, while an electronic version brakes the spinning wheel instead. The result is cleaner corner exits, more usable traction in the wet, and a car that puts power down rather than lighting up one tyre.

When you actually need one

The more power you have and the harder you corner, the more an LSD matters. Track use, powerful front-wheel-drive cars fighting wheelspin, and rear-drive cars on low-grip surfaces are the classic cases. A modest daily driver on normal roads often manages fine on an open diff plus traction control. Fitting an LSD can also add drivetrain noise or slight low-speed harshness, so match the type to how you drive.

The conditions that matter

• ✓An LSD improves traction out of corners and on low-grip surfaces.
• ✓It is most worthwhile on powerful or track-focused cars.
• !Clutch-type units can add noise and wear, and need servicing.
• !A gentle road car may not gain much over an open diff plus traction control.

General guidance only. Details vary by exact vehicle and change over time; confirm with a reputable specialist before modifying.